<?php

/**
 *   加密工具类
 *  modify by phl   原本是方法来的,因为和框架的方法重名。我改成了静态类方法
 * User: jiehua
 * Date: 16/3/30
 * Time: 下午3:25
 */
class AopEncrypt
{
    /**
     * 加密方法
     * @param string $str
     * @return string
     */
    public static function encrypt($str, $screct_key)
    {
        //AES, 128 模式加密数据 CBC
        $screct_key  = base64_decode($screct_key);
        $str         = trim($str);
        $str         = self::addPKCS7Padding($str);
        $iv          = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC), 1);
        $encrypt_str = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $screct_key, $str, MCRYPT_MODE_CBC);
        return base64_encode($encrypt_str);
    }

    /**
     * 解密方法
     * @param string $str
     * @return string
     */
    public static function decrypt($str, $screct_key)
    {
        //AES, 128 模式加密数据 CBC
        $str         = base64_decode($str);
        $screct_key  = base64_decode($screct_key);
        $iv          = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC), 1);
        $encrypt_str = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $screct_key, $str, MCRYPT_MODE_CBC);
        $encrypt_str = trim($encrypt_str);

        $encrypt_str = self::stripPKSC7Padding($encrypt_str);
        return $encrypt_str;

    }

    /**
     * 填充算法
     * @param string $source
     * @return string
     */
    public static function addPKCS7Padding($source)
    {
        $source = trim($source);
        $block  = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

        $pad = $block - (strlen($source) % $block);
        if ($pad <= $block) {
            $char   = chr($pad);
            $source .= str_repeat($char, $pad);
        }
        return $source;
    }

    /**
     * 移去填充算法
     * @param string $source
     * @return string
     */
    public static function stripPKSC7Padding($source)
    {
        $source = trim($source);
        $char   = substr($source, -1);
        $num    = ord($char);
        if ($num == 62) return $source;
        $source = substr($source, 0, -$num);
        return $source;
    }

}